Flashing Grade Silicone or Silicone Caulk?
We all know how important it is to order the right amount of material when starting a new silicone roof restoration job. If you order too little, you may extend the project lifespan while you wait for the remaining product to ship. If you order too much material, you can always use it on future products, but will tie up some cash until then. With this is mind, we wanted to take a look at a couple of products for which it can be difficult to calculate material requirements- our FG 400 series Flashing Grade Silicone (FGS) and our SS 300 series Silicone Caulk (SS).
When inspecting a roof, there are many instances where FGS and SS are necessary. Both are high viscosity materials that are more mold-able than our 3200 or 2200 topcoat silicones. They are used in the preliminary phases of the restoration and are crucial to ensuring a watertight, seamless topcoat. In this article we will look into the differences between the two products to help you determine when to order each one.
Flashing Grade Silicone (FGS)
Flashing Grade Silicone is one of our top selling products thanks to its strength, adhesion, and versatility. It is primarily used during the roof prep phase but can also be applied as touch-ups are needed. FGS can be useful for sealing seams, fasteners, flashings, cracks, or hard to reach roof features. It is specifically designed to seal abnormal roof penetrations and areas where fish-mouthing or weakened substrates make achieving a seamless final membrane impossible.
You can apply FGS with a paint brush for coating seams or fastener heads. The “butter” consistency makes application very simple while offering a workable product that can help seal off trouble areas. FGS is commonly utilized on larger cracks, gaps, or worn areas and should be applied generously to fully seal any of these open areas. The simple 2-step application process makes FGS an even more appealing product:
- Clean the area needing repair with a rag.
- Apply flashing grade silicone with a paint brush or putty knife.
We carry flashing grade in 4 standard colors: white, black, gray, and clear. However, if you only have white FGS but have a roof coated in HS 3203 light gray, simply wait for the flashing grade to cure and coat over the area again with HS 3203.
Silicone Sealant Caulk (SS)
SS 300 Series is another fix-all type of product, but its uses are a bit different than FGS. You will want to order SS for any smaller, more precise cracks or worn areas. Like most caulks, SS applies using a caulk gun which makes it easy to target trouble areas with precision. Having SS on hand will ensure accuracy for any small areas or hard to reach places such as behind an AC unit, under conduit, etc.
SS is useful to have on hand during prep work, but it’s also a great product to have in every work truck as well. While walking a roof, it’s pretty frequent that you might make a small cut into a substrate to inspect for water damage or other issues. Having SS with you will allow you to re-patch those areas quickly and inexpensively. Similar to FGS, Silicone 
Caulk has a simple application process:
- Clean the area needing repair with a rag.
- Apply caulk with a caulk gun.
- Smooth out with your finger or a putty knife.
Conclusion
In terms of product ordering, it’s safe to assume you will need far more FGS than SS on most jobs. Flashing Grade’s functionality and easy-to-use application makes it a must-have on any coatings project. Keeping a case of SS 300 on the jobsite, however, will guarantee you’re able to seal with precision. Caulk is a great example of what we said earlier: if you order too much for the current project, you can use it on later projects no problem!
Whenever you are walking a roof or quoting a project remember that our Regional Managers are here to help! It can be difficult to determine exactly how much coating you need, but with our team of experts we can get you very close. If you are looking for some assistance on quoting a project, you can find your Regional Manager here: https://pmsilicone.com/find-your-representative/
